Multiple-flow liquid ring pump

ABSTRACT

The invention relates to a multiflow liquid ring pump, comprising a rotor housing that encompasses the pump rotor. A side shield is arranged on both front ends. Each side shield has an inlet and an outlet on the side facing the other side shield, the inlet and outlet being interconnected. An admission hole for the feed line and a pressure hole for the discharge line are provided. Each side shield has at least one additional connection hole. The invention is characterized in that the outer jacket surface of each side shield ( 3, 4 ) flushes with and closes the outer jacket surface of the rotor housing ( 2 ) and in that the inlet ( 7, 9 ), the outlet ( 8, 10 ) and the connection hole ( 11, 12, 13, 14 ) are connected by channels ( 15, 16, 30, 31 ) arranged in the rotor housing ( 2 ).

FIELD OF THE INVENTION

The invention relates to a multiple-flow liquid ring pump.

DESCRIPTION OF RELATED ART

A liquid ring pump is known from U.S. Pat. No. 4,132,504. The rotorhousing has a substantially circular cross-section. Ribs of lengthwiseextension, which stand out radially and which, towards the inside,define channels, are disposed on the surface, in the shape of a cylinderjacket, of the rotor housing. A drawback of this arrangement resides inthat the space maximally taken by the housing of the liquid ring pump,i.e., height times width, is substantially greater than needed by thecylinder-jacket shape of the rest of the rotor housing. Moreover, theprojecting ribs form dead spaces where dirt can accumulate. Further,handling the liquid ring pump is accompanied with the risk that someonemight be caught by the projecting ribs.

A liquid ring pump of the species is known from EP 0 584 106 B1. It is amultiple-flow liquid ring pump having a rotor housing which surroundsthe rotor of the pump and on each of the two end sides of which a sideshield is arranged. The two side shields extend beyond the rotor housingin the radial direction and each side shield has, in its projectingregion, an inlet opening and an outlet opening on the side facing theother side shield. These openings are connected to each other byconnecting tubes which extend parallel to the rotor housing, a suctionopening being provided for a feed line and a delivery opening for adischarge line. Further connecting openings can be provided in the twolower corners, serving for the supply of operating liquid and/or forpressure compensation between the two halves of the pump. These openingsare also connected via tubes that are parallel to the rotor housing. Asupport arm is molded on both side shields, comprising the bearings forthe shaft of the rotor.

A drawback of this construction resides in the space required by thebearing disposed in the support arm and in the increased mountingrequirements for the installation of the connecting tubes. The highnumber of projecting parts in the overall construction, such as thesupport arm and the connecting tubes, form nests for the accumulation ofdirt which is rather difficult to remove.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a liquid ring pump of thegeneric type which is more compact and space-saving as compared to theknown prior art.

Attaining this object proceeds from the preamble of claim 1, taken inconjunction with the characterizing features thereof. Advantageousembodiments are specified in the sub-claims.

According to the invention, the outer jacket surface of each side shieldis flush with the outer jacket surface of the rotor housing and theconnection of the inlets and outlets as well as the connecting portstakes place via channels disposed in the rotor housing. This type ofarrangement has the advantage that there are no projecting componentsforming nests for the accumulation of dirt, the whole aggregateconsequently being cleaned more easily. Another advantage resides inthat there is no need for the installation of separate connecting tubes,because they are an integral part of the rotor housing. They can forexample be cast directly during manufacture. The side shields can easilybe flanged on the respective end face of the rotor housing by means ofthrough-bolts. The cross section of the rotor housing is approximatelysquare, the side faces being curved slightly outwards and rounded wherethey pass into the areas of the lateral edges. The connecting channelsare located in the crotches which result between the rotor housing ofnearly square cross-section and the round working area, the working areabeing approximately centric of the rotor housing. Approximately meansthat the working area is either equi-axed or by some millimeterseccentric of the rotor housing. For example, the axis of the workingarea is eccentric of the axis of the rotor housing by five millimetersin the direction of the twelve o'clock position. Regardless of theeccentricity which correlates with the dynamic operating performance ofthe pump, the drill hole of the rotor housing can be displaced relativeto the outer contour, preferably in the direction of the 6 o'clockposition. As a result, centric of the rotor housing. Approximately meansthat the working area is either equi-axed or by some millimeterseccentric of the rotor housing. For example, the axis of the workingarea is eccentric of the axis of the rotor housing by five millimetersin the direction of the twelve o'clock position. Regardless of theeccentricity which correlates with the dynamic operating performance ofthe pump, the drill hole of the rotor housing can be displaced relativeto the outer contour, preferably in the direction of the 6 o'clockposition. As a result, the incorporated cross-sectional geometry of theupper suction and pressure channels can be made greater than the lowerchannels for operating liquid and dirt particles. The advantage consistsin that by this measure, the cross-sectional areas can be adapted to therequired volume flows and the flow rates resulting therefrom.

In known manner, one of the lower connecting ports is provided for thesupply of operating liquid. According to the invention, the secondconnecting port is a dirt particle discharge channel provided withconnecting channels which are radial of the working area. In this way,any dirt particles entrained are catapulted off by centrifugal forces inthe working area and are forced by the centrifugal forces through theports in the wall of the working area into the lengthwise dischargechannel. At certain intervals, the dirt particles accumulated in thedischarge channel can be removed.

So as to render the installation of the connecting lines as flexible aspossible, depending on the situation of incorporation, a furtherdevelopment of the invention proposes to skew the end face area of theside shield that is turned away from the rotor housing and possesses theinlet and outlet opening. Preferably, this skew is in the range of 45°.This has the advantage that the supply line can be installed, savingspace upwards as well as forwards. In like manner, inlet and outletopenings of equal design are formed on both side shields; they can beclosed alternately so that the connection of the supply line and thedelivery line may take place optionally on one of the two sides of theliquid ring pump. This principle of optional supply from one side or theother also applies to the operating liquid. Distribution to thenecessary places then takes place via the connecting channel integratedin the rotor housing. For the purpose of avoiding any accumulation ofdirt particles and having a compact constructional design, the inventionprovides the sealing as well as the bearing arrangement of the rotorshaft to be integrated in both side shields. Preferably, the sealingarrangement is disposed in a sealing housing and the bearing arrangementin a separate bearing housing. Both housings are screwed together andsealed. The advantage of this arrangement resides in that the unit ofthe sealing and bearing housing can be detached completely by beingpulled off the rotor shaft. In this case, the rotor shaft is placed ontwo noses integrated in the respective cam disk. In this way it ispossible to replace worn-out shaft packing rings without the entiremachine having to be detached from the vehicle and dismantledcompletely.

Details of the invention will become apparent from the ensuingdescription of an exemplary embodiment of the multiple-flow liquid ringpump, taken in conjunction with the drawing, in which

BRIEF DESCRIPTION OF THE SEVERAL VIEW OF THE DRAWINGS

FIG. 1 is a perspective view of a multiple-flow liquid ring pumpaccording to the invention;

FIG. 2 is an elevation of a side shield in the cast condition;

FIG. 3 is a sectional view on the line A—A in FIG. 4;

FIG. 4 is a sectional view on the line B—B in FIG. 2;

FIG. 5 is a sectional view on the line D—D in FIG. 4;

FIG. 6 is a sectional view on the line E—E in FIG. 5;

FIG. 7 is a sectional view on the line C—C in FIG. 2;

FIG. 8 is a longitudinal sectional view of the multiple-flow liquid flowpump according to the invention;

FIG. 9 is a sectional view on the line F—F in FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a perspective view of a multiple-flow liquid ring pump 1 of adesign according to the invention. It comprises a rotor housing 2 andtwo side shields 3, 4 attached thereto. The side shield 3, which lies infront in this illustration, constitutes the driving end with the rotorshaft 5 actuating the pump. This illustration clearly shows that theside shields 3, 4 are flush with the outline of the rotor housing 2.Each side shield comprises recesses 6 on both side faces, taking upthrough-bolts for the fastening of the side shields 3, 4 on therespective end face of the rotor housing 2. Openings 7, 8 are providedin the upper portion, the opening 7 on the left of the front side shield3, in this embodiment, being the inlet for the suction side and theopening 8 on the right being the outlet for the delivery side. The rearside shield 4 comprises identical openings 9, 10. According to theinvention, the lower portion of each side shield 3, 4 has at least oneconnecting port 12, 14, preferably for the supply of the operatingliquid. However, another connecting port 11, 13 can be provided forinstance as a dirt particle discharge channel. The openings 9, 10 andthe connecting ports 13, 14 of the rear side shield 4 cannot berecognized in this illustration.

The subsequent FIGS. 2-7 illustrate details of the side shield 3 and 4,respectively, according to the invention. FIG. 2 shows the side shield3, which lies in front in FIG. 1, in the cast condition. As can be seen,the inlet and outlet openings 7, 8 are incorporated during casting,whereas the lower connecting ports 11, 12 (FIG. 1) still have to bedrilled.

FIGS. 3-7 are sectional or partial sectional views of the guidance ofthe channels within the side shield 3 here under regard. Owing to thedouble-flow design of the machine (see FIG. 8), the side shield 3, 4enables the distribution of the gas, to be supplied or discharged, totake place into the chamber on the right in FIG. 8 on the one hand andvia the channels 15, 16, which are disposed in the rotor housing 2, intothe chamber on the left in FIG. 8 on the other hand. This is true forthe suction side 17 as well as for the delivery side 18.

Each side shield 3, 4 comprises a central stepped hole 19 for theaccommodation the sealing arrangement and the bearing for the rotorshaft 5 (FIG. 8). The respective cam disk 21, 22 (FIG. 8) is mounted onthe internal end face 20 by means of screws 47 (FIG. 8). This end face20 also comprises a centering shoulder 23 which stands out and on whichthe rotor housing 2 is centered. The supply of operating liquid takesplace via the connecting port 12 and the channel 24, which extends inthe side shield 3, via a hole 25 into the bearing area 19. From there itflows on via the opening 26, 27 provided in the respective cam disk 21,22 into the working area of the respective chamber of the machine.According to FIG. 6, rigidifying ribs 28 are provided for thereinforcement of the respective side shield 3, 4.

FIG. 8 once again illustrates the entire correlation in a longitudinalsectional view and FIG. 9 in a sectional view of the line F—F in FIG. 8.An arrow 29 characterizes the selected direction of rotation of therotor shaft 5 and thus of the pump in FIG. 9. Of course the direction ofrotation may also be clockwise, but this would mean an interchange ofthe suction side 17 and the delivery side 18. This sectionalillustration offers a clear view of the upper channels 15, 16 which jointo each other the inlet and outlet openings 7, 9 and 8, 10,respectively, of the two side shields 3, 4. Further channels 30, 31 areprovided in the lower crotches, preferably serving to pass the operatingliquid on, but also to function as dirt particle discharge channel. Theoutline of the rotor housing 2 is substantially square with bulging sidefaces. The side faces are equipped with ribs 32.

The longitudinal sectional view of FIG. 8 illustrates the two-chambersystem with the central rib 33 dividing the two chambers. Strictly seen,the inlet openings 7, 9 in the side shields 3, 4 do not lie in thislongitudinal section, however, for reasons of understanding, they havebeen projected on the plane of the drawing. In accordance with theillustration of FIG. 4, the chambers ought to be closed in thislongitudinal sectional view.

As opposed to the known prior art, the sealing as well as the bearingarrangements of the rotor shaft 5 are integrated in the two side shields3, 4. In this embodiment, the sealing arrangement comprises a glandpacking 34 and three side by side shaft lip seals 35-37, the lips of theinward shaft lip seals 35, 36 inclining to the left and the lip of theoutward shaft lip seal 37 inclining to the right. A grease sealingarrangement is provided between the two first shaft lip seals 35, 36,the filling of which takes place via a hole 38. Relief takes place viaanother hole 39. By alternative to the arrangement herein illustrated ofshaft lip seals 35-37, axial face seals are conceivable too. The bearing40—in this case in the form of a spherical roller bearing—is disposed onthe seat of the bearing of the rotor shaft 5. The bearing 40 is fixedaxially by a shaft nut 41 which can be screwed on. A cover 42 or cap 43,respectively, constitutes the lateral end, having a sealed opening forthe shank of the rotor shaft 5 to pass through. The respective sealingarrangement is disposed in a sealing housing 48 and the respectivebearing arrangement in a bearing housing 49. Both housings 48, 49 arescrewed together, a seal 50 being disposed between the stop faces of thetwo housings 48, 49.

For the possibility of discharging the operating liquid whenevernecessary, plugs 43, 44 are provided in the lower part of the respectiveside shield 3, 4 so that the operating liquid can be discharged from theright as well as from the left. Further, the illustration broken open atthe lower right shows two plugs 45, 46 so that the supply of operatingliquid can take place optionally from the end face of the side shield 3or from the underside. For completion it must be mentioned that theinlet and outlet openings 7, 9 and 8, 10, respectively, in the two sideshields 3, 4 can be closed optionally so that the connection of linesmay take place optionally on the left and on the right side shield 3, 4.All the options mentioned above have been considered deliberately duringconstruction for high flexibility in the choice of possible connectionsto be obtained. This is accompanied with the advantage that it is up toevery operator to decide from which side to connect the lines mostfavorably.

What is claimed is:
 1. A multiple-flow liquid ring pump (1) comprisinga) a rotor housing (2) which encompasses a rotor disposed in a workingarea and two end faces; b) side shields (3, 4) disposed on both endfaces, i) each side shield (3, 4), on the side turned towards the otherside shield, having an inlet opening (7, 9) and an outlet opening (8,10) which are interconnected, ii) a suction port being provided for asupply line and a pressure port for a delivery line, iii) and each sideshield having at least one further connecting port (11, 12, 13, 14); c)the outer jacket surface of each side shield (3, 4) being flush with theouter jacket surface of the rotor housing (2); and d) the connection ofthe inlet (7, 9) and outlet opening (8, 10) as well as of the connectingport (11, 12, 13, 14) taking place via channels (15, 16, 30, 31)disposed in the rotor housing (2); characterized in that e) the rotorhousing (2) has a substantially rectangular cross section; f) theworking area has a round cross section and is disposed substantiallycentric of the rotor housing (2); and g) the channels (15, 16, 30, 31)are disposed in crotches in the rotor housing (2) which ensue from theround working area.
 2. A liquid ring pump (1) according to claim 1,characterized in that the rotor housing (2) has a substantially squarecross section, the side faces being slightly curved outwards and roundedwhere they pass into the lateral edge portion.
 3. A liquid ring pump (1)according to one of claims 1 or 2, characterized in that in one of thetwo lower crotches, one side shield (3, 4) or both side shields (3, 4)as well as the rotor housing (2) have only a single connecting port (11,12, 13, 14) as well as a connecting channel (30, 31) for the supply ofoperating liquid.
 4. A liquid ring pump (1) according to one of claims 1or 2, characterized in that in both lower crotches, one side shield (3,4) or both side shields (3, 4) as well as the rotor housing (2) haveeach a connecting port (11, 12) as well as a connecting channel (30,31), one of the two connecting channels (30, 31) being a dirt particledischarge channel with connecting channels extending radially towardsthe working area.
 5. A liquid ring pump (1) according to one of claims 1to 4, characterized in that the side-shield end face area which isturned away from the rotor housing (2) and which comprises the inlet (7,9) and outlet opening (8, 10) is skewed.
 6. A liquid ring pump (1)according to claim 5, characterized in that the skew amounts to 45°. 7.A liquid ring pump (1) according to one of claims 1 to 6, characterizedin that the inlet (7, 9) and outlet openings (8, 10) of identicaldesign, which are disposed on the side shields (3, 4), are alternatelyclosable.
 8. A liquid ring pump (1) according to one of claims 1 to 7,characterized in that the sealing as well as the bearing arrangement forthe rotor shaft (5) are integrated in both side shields (3, 4).
 9. Aliquid ring pump (1) according to claim 8, characterized in that thesealing arrangement is disposed in a sealing housing (48) and thebearing arrangement in a bearing housing (49) and the two housings (48,49) are screwed together in a manner sealed (50) towards each other.